Power locks just quit working

These are all controlled via the Body Control Module. This type of vehicle has some of this operation built into the engine computer too. The relays carbon-up &/or go dry-jointed inside of the BCM's. They need a re-work and relay contacts all need cleaning, which you can do yourself by pinching a non-glossy business card between the relay contacts and sliding it out until the black carbon trace disappears. De-solder, clean, flux, re-solder dry joints on relays and connectors. I've personally done hundreds over many years.